Roller skate, commonly known as skates, ice skates, comprising a skate body and a wheel assembly is a product combining entertainment with fitness and is popular with many people, especially youngsters, while having numerous applications. Currently the wheel of the roller skates in market is not fixed, cannot be adjusted up and down and only skids on a plat ground, therefore the wheel cannot cross once an uneven ground is encountered thereby leading to great security risks. It is necessary to improve against such a structure of the present roller skates by allowing the roller skates to adapt to an uneven ground, so as to increase the flexibility and experience for its use.